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To achieve the goal of 'carbon neutrality', it is of great significance to accelerate the process of dismantling high-carbon and high-pollution thin-walled cylinder structures such as chimneys and so on. A 183 m ultra-high coaxial thin-walled steel-inner-cylinder reinforced concrete chimney (UCTS-RCC) was successfully demolished for the first time. To successfully dismantle the UCTS-RCC by controlled blasting demolition technology, the necessary structural mechanics theoretical analysis and the critical blasting designs rationality verification were carried out. Based on the equilibrium equation of force and bending moment, a theoretical model of incision angle selection was established to determine the incision design of the steel inner cylinder (SIC). The stability of SIC under the designed incision parameters was verified based on FEM statics analysis. The cutting experimental on the target steel plate was completed with a linear shaped cutter to obtain the cutting effect. The cutting process and the overall collapse process of the UCTS-RCC were simulated by LS-DYNA. Based on the fixed axis rotation differential equation, the synchronous toppling theoretical model were established to study the motion of the UCTS-RCC. The results showed that the maximum stress at the position of the directional window and the stresses of the remaining supports were less than the yield limit of Q235B steel after that several pretreatment windows were carried out, the SIC could maintain the stability of remaining structures. The cutting experimental results of the target steel plate using linear shaped cutter were basically consistent with the cutting simulation and the cutting effect satisfied the design requirements of instantaneous cutting separation of the supports. According to the obvious difference of material properties between Q235B steel and reinforced concrete, the ignition delay time of the SIC was set 2 s earlier than that of the RCC. According to the synchronous collapse simulations, it could be known that the ignition delay time setting was reasonable and the collapse motion state of the UCTS-RCC was approximately fixed axis rotation, which was in line with the established synchronous toppling theory model. The SIC and RCC finally successfully collapsed synchronously. The blasting scheme and the rationality verification methods were applied successfully in this project, which was of great significance to provide a reliable reference for such ultra-high thin-walled cylinder complex structural chimney.

A large number of Chinese herbal medicines (CHMs) are included in daily recipes, but their pesticide residues have aroused more and more concerns. In this paper, an electrochemiluminescence aptasensor was constructed for the trace detection of acetamiprid (ACE) in Angelica sinensis and Lycium barbarum. Possessing a large specific surface area, UiO-66 was modified with amino groups to improve biocompatibility, and the addition of AuNPs allowed UiO-66-NH 2 to catalyze the formation of excited states of luminescent molecules (TPrA ⁎ ; Ru(bpy) 3 2+ ⁎ ), and AuNPs@UiO-66-NH 2 was used to bridge the aptamer (Au-S) and luminescent substrate (peptide bond). The conventional luminescent reagent Ru(bpy) 3 2+ was doped with multi-walled carbon nanotubes (MWCNTs) to obtain a more powerful and stable light signal. After optimizing the experimental parameters, the aptasensor could give results in 10 min with a detection range from 1×10 -2 -1×10 4  nM and a lower limit of detection (LOD) of 0.8 pM. The LOD of the study was at least one order of magnitude lower than that of the fluorescence detection method. Furthermore, the accuracy of the aptasensor was validated for spiked recovery experiments., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Penicillin antibiotics (PENs) play an important role in killing pathogenic bacteria. However, the residues of various penicillin antibiotics in milk gradually accumulate in the human body with the increase of milk intake, which causes direct harm to the human body. Aptamers can be used as recognition element of sensors. It is great significance to use broad-spectrum aptamers for simultaneous detection of PENs. In this study, we reported the screening and identification of DNA aptamers for PENs. The aptamers were screened by graphene oxide-systematic evolution of ligands by exponential enrichment (GO-SELEX). The broad-spectrum aptamers with high affinity and specificity were successfully obtained after 13 rounds of screening. The affinity and specificity of candidate aptamers were analyzed by a GO fluorescence competition method. Further sequence analysis revealed that a truncated 47 nt aptamer (P-11-1) had a higher affinity than the original 79 nt aptamer. The truncated aptamer P-11-1 was used as a recognition element, and an electrochemical aptasensor was prepared using gold nanoparticles (AuNPs) combined with ferroferric oxide-multi walled carbon nanotube (Fe 3 O 4 -MWCNTs) complex. The results showed that the developed aptasensor achieved the simultaneous detection of PENs in milk samples across a concentration range of 2 nM-10,000 nM, achieving a limit of detection of 0.667 nM. This methodology provided a simple and sensitive new thinking for antibiotic multi-residue detection., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)